Seedlings under 400W MH

I recently upgraded to 2 tents. One 600w hps and one 400wmh. Due to where I live I'm skeptical of running another light... my old t5 to veg seedlings under. My 400w mh is about 3 ft away from soil. They're just starting to sprout so I'm getting kind of antsy.


Nope your ok.. ;) But remember, you do not want to bombard them with too much light soon as they pop . You'll create stresses right off the bat. That being said, as long as you keep the light at It's best optimal range. You can raise a perfectly healthy plant, without "bleaching". Here's a guide/chart to help you out ;)
marijuana_chart.jpg


I would personally just try to make a space for them under a T5 or T8. But, if you follow this chart things should generally be ok.:Namaste::high-five:


PS: Post some pics of your set up! :popcorn:
 
I'll get some pics for ya tonight for sure. I'll check out your journal as well. My issue with setting up my t5 simultaneously is the power useage. I've went from a 200w t5 to a 400w hps to a 400w mh and a 600w hps. Not to mention fans. My sad attempt at bubble cloning and everything else that uses power. So long as I CAN KEEP THEM ALIVE (lol) I'll see what happens under the mh. Hopefully all goes well. I could dim to 75% but would that negatively affect my old vegging plants?
 
I see. :( , & thanks a quick link is in my signature ;)

As long as they are getting a good source of light without any darkness they shouldn't be effected to much. If you drop to 75% they should still be fine. They might even stretch/grow more because they will try to reach for the light as much as possible. Just make sure they are getting a consistent light source for more then 16 hours a day and you'll be :thumb:
 
And my next question is.... would it be better to put my mh veg light to the top of my tent or should I keep it low? This is an in general question of vegging plants not just seedlings. Should I put it higher to create a stretch of sorts or should I keep it low? They are about 2 ft above my canopy on actual vegging plants. There are pictures in my journal.

Well, there is no differences between all the different lights. Only the spectrum and output. So if you want to stretch your plants I would keep the MH farther away & vice versa if you want bushy plants, keep it closer to the canopy.. The only difference in MH and HPS is spectrum output. MH has more of the blue spectrum and HPS has more of the red. (Is why MH is generally better for vegging then HPS. But MH can be used to grow in all stages of the plants life)
 
I've been growing all stages of vegging plants under the mh for years. It's dimmable from 300-600 but I'm usually at 600, or 400 if I want them to slow down a bit. I think you won't find any issues. I put the smaller ones down lower and sometimes tucked under the larger plants a bit, which is how things would work out in nature.
 
That wattage is so low it is not really noticable. All of that on is like having about 12-15 100W standard light bulbs on in the place (accounting for some efficiency losses). Change all your bulbs in the house to CFLs and it will go unnoticed. You really need to be at like 4 or more 1000Ws to be noticed. Your computer if it is a tower has probably a 600W supply on it.
 
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